msm: ipa: use bitmap for wakelock ref_count

Current wakelock ref_count is shared with all
the clients. There is a possibility that each
client could increase wakelock ref_count by
accident. Change the wakelock ref_count to bitmap
so each client can only update its own bit once.

Change-Id: I87f47cf54dc34a76dc2c4a537108f9be7b6bdba8
Signed-off-by: Skylar Chang <chiaweic@codeaurora.org>